In recent decades, vapor cloud explosions (VCEs) have occurred frequently and resulted in numerous personnel injuries and large property losses. As a main concern in the petrochemical industry, it is of great importance to assess the consequence of VCEs. Currently, the TNT equivalency method (TNT EM), the TNO multi-energy method (TNO MEM), and the Baker-Strehlow-Tang (BST) method are widely used to estimate the blast load from VCEs. The TNO MEM and BST method determine the blast load from blast curves based on the class number and the flame speed, respectively. To quantitatively evaluate the flame speed for the BST method, the experimental data is adopted to validate the confinement specific correlation (CSC) for the determination of the class number in the TNO MEM. As a bridge, a quantitative evaluation correlation (QEC) between CSC correlation and the flame speed is established and the blast wave shapes corresponding to different flame speeds are proposed. CFD software FLACS was used to verify the quantitative correlation with the numerical models of three geometrical scales. It is found that the calculated flame speeds by the QEC are in good agreement with the simulated ones. A petrochemical plant is selected as a realistic scenario to analyze the TNT EM, TNO MEM, BST method and FLACS simulations in terms of the positive-phase side-on overpressure and impulse at different distances. Compared with the flame speed table, the predicted overpressure from BST curves determined by the proposed QEC is closer to that from FLACS and more conservative. Furthermore, the predicted results of different methods are compared with each other. It is found that the estimated positive-phase side-on overpressure and impulse by the TNO MEM are the largest, and the estimated impulse by the TNT EM is the smallest. Moreover, the estimated overpressure and impulse are larger in the higher reactivity gas.

近几十年来，蒸气云爆炸 (VCE) 频繁发生，造成大量人员伤亡和重大财产损失。作为石化行业的主要关注点，评估 VCE 的后果非常重要。目前，TNT 等效法 (TNT EM)、TNO 多能法 (TNO MEM) 和 Baker-Strehlow-Tang (BST) 方法被广泛用于估计 VCE 的爆炸载荷。TNO MEM 和 BST 方法分别根据类别编号和火焰速度从爆炸曲线确定爆炸载荷。为了定量评估 BST 方法的火焰速度，采用实验数据来验证约束特定相关性 (CSC)，以确定 TNO MEM 中的类号。作为一座桥梁，建立了CSC相关性与火焰速度之间的定量评估相关性（QEC），并提出了不同火焰速度对应的爆炸波形。使用CFD软件FLACS验证与三个几何尺度数值模型的定量相关性。发现 QEC 计算的火焰速度与模拟的非常吻合。选择石油化工厂作为现实场景，根据不同距离的正相侧向超压和脉冲分析 TNT EM、TNO MEM、BST 方法和 FLACS 模拟。与火焰速度表相比，由所提出的 QEC 确定的 BST 曲线预测的超压更接近 FLACS，并且更保守。此外，将不同方法的预测结果相互比较。发现TNO MEM估计的正相侧向超压和冲量最大，TNT EM估计的冲量最小。此外，在较高反应性气体中估计的超压和脉冲较大。